In an effort to limit the damage, the administration is working with news organizations to whom WikiLeaks has given the documents to redact sensitive names, but there is no guarantee that WikiLeaks won't simply publish unredacted documents.

The U.S. government has also already started to notify allies and U.S. lawmakers about potentially damaging information, which it said could endanger lives and harm national security.

"We are in touch with our posts around the world. They have begun the process of notifying governments that the release of documents is possible in the near future," State Department spokesman P.J. Crowley told reporters at a press briefing Wednesday.

U.K. officials confirmed today that U.S. authorities had already briefed them about the possible WikiLeaks release, and the U.S. government had also reportedly reached out to Israel, Australia and Canada, among other countries.

State Dept: Leak 'Could Create Tension'

Crowley did not provide specifics on the content of the documents, although he did say they contained classified discussions, analysis and perspectives that could harm diplomatic relations if released. According to The Associated Press, some of the information is so serious it could result in American diplomats getting expelled by foreign governments.

"This back and forth between government, the government of the United States and governments around the world, it is diplomacy in action," Crowley said. "These revelations are harmful to the United States and our interest. They are going to create tension between our diplomats and our friends around the world."

On its Twitter page in recent days, WikiLeaks appears to be taunting U.S. authorities.

"The Pentagon is hyperventilating again over fears of being held to account," the organization wrote on Nov. 23.

"Should WikiLeaks expose the world's secret diplomatic backroom dealings? Put it to the vote!" it posted in another tweet Thursday, providing a link to an online poll.

U.S. Ambassador Calls WikiLeaks 'Absolutely Awful,' Could Harm U.S. Efforts

In Baghdad today, U.S. Ambassador to Iraq James Jeffrey confirmed that the WikiLeaks documents could do serious harm to U.S. diplomatic efforts.

"WikiLeaks are an absolutely awful impediment to my business, which is to be able to have discussions in confidence with people," Jeffrey told reporters at a briefing, according to news agency AFP. "I do not understand the motivation for releasing these documents. They will not help. They will simply hurt our ability to do our work here."